I see the argument often on social media—some christians claiming that once one is saved, it is permanent, and some asserting that salvation can be lost, or “forfeited” by someone who turns his back on his belief.
The primary problem in the debate is that, typically, neither side actually knows what it means to be born again, why it happens, how it happens, or what evidence is given to those who have received it. Part of this comes from thinking that “being a christian” means that one is born again. That is false. Being a christian is really nothing more than choosing to join a club. Being born again is an act of the Father, not of man.
In very large measure, the “salvation” taught by christianity is something that a person chooses to have—he makes a decision, prays a prayer, or declares that he has “accepted Christ into his heart” (just narrowly missing a lung). But, salvation is not controlled by man—only his belief is. Being born again is the future result of genuine belief, and faithfulness to that belief (1 Peter 1:9).
In christianity, man declares that he is saved. But, in real salvation, the Holy Spirit declares TO the believer that he has been made a child of Yah—he has been given the covenant. In christianity, it is taught that the moment a person makes a human decision, he is immediately given the Holy Spirit. That is absurd.
Often, christians will vehemently argue they have the Spirit, even though they have not received any actual confirmation from Him about that. In fact, most don’t know what that confirmation even is, and many think that the Holy Spirit doesn’t even communicate directly with people anymore. They merely equate their feelings about things they have read and heard to be the Holy Spirit. He is not a feeling.
So, when the two sides are debating over something that is the work of a man’s decision, then neither is correct, for one cannot lose something he never actually had in the first place.
For more information: Once Saved Always Saved?